Exchange Management Shell error

I'm receiving a strange error when running a EMS cmdlet. I have an 2003/2010 Exchange organization. There are two active directory sites. Site 1 has 3 domain controllers and Site 2 has one domain controller. In Site 1 we have 1 Exchange 2003 server, 2 Exchange 2010 HT/CAS servers, and 3 Exchange 2010 Mailbox Servers. All 2010 servers are SP1 RU 6.

MBX1,2,3 are in a DAG (DAG1). From both a HT/CAS and an MBX server, I am running the cmdlet: Get-ExchangeServer | where {$_.ismailboxserver -eq $true} | Get-MailboxDatabaseCopyStatus. From both, I receive the same error:

The operation couldn't be performed because object 'MLK-MBX-01' couldn't be found on 'DC1.mlk-austin.local'.
    + CategoryInfo          : NotSpecified: (:) [Get-MailboxDatabaseCopyStatus], ManagementObjectNotFoundException
    + FullyQualifiedErrorId : 925FC0C8,Microsoft.Exchange.Management.SystemConfigurationTasks.GetMailboxDatabaseCopySt
   atus

The operation couldn't be performed because object 'MLK-MBX-02' couldn't be found on 'DC1.mlk-austin.local'.
    + CategoryInfo          : NotSpecified: (:) [Get-MailboxDatabaseCopyStatus], ManagementObjectNotFoundException
    + FullyQualifiedErrorId : 34A67423,Microsoft.Exchange.Management.SystemConfigurationTasks.GetMailboxDatabaseCopySt
   atus

The operation couldn't be performed because object 'MLK-MBX-03' couldn't be found on 'DC1.mlk-austin.local'.
    + CategoryInfo          : NotSpecified: (:) [Get-MailboxDatabaseCopyStatus], ManagementObjectNotFoundException
    + FullyQualifiedErrorId : C90EFBBE,Microsoft.Exchange.Management.SystemConfigurationTasks.GetMailboxDatabaseCopySt
   atus

Can anyone provide assistance on why this may be happening? AD replication is working correctly.